The state filed its appeal without comment through the U.S. Court of Appeals for the Fourth Circuit, according to court documents.

The action comes less than a month after U.S. District Court Judge James Fox ruled: "The State's offering a Choose Life license plate in the absence of a pro-choice alternative constitutes viewpoint discrimination in violation of the First Amendment."

The ruling was praised by the American Civil Liberties Union, which had filed a lawsuit in 2011 to stop the specialty plates.

The ACLU called Friday's appeal "unfortunate."

"It's unfortunate that the state has chosen to prolong what is really a very clear-cut First Amendment issue," said Chris Brook, legal director of the ACLU's North Carolina Legal Foundation. "The Fourth Circuit Court of Appeals has consistently ruled that any time the government creates an avenue for private speech, it cannot restrict that avenue to only one side of a contentious debate."

The bill for the license plates passed in 2011. The legislation also mandated that money raised from the sale of the specialty plates would go to a nonprofit group that supports crisis pregnancy centers, CNN affiliate WRAL reported.

During the fight to get the bill passed, North Carolina lawmakers voted down amendments that would have created alternatives for abortion-rights supporters such as "Trust Women. Respect Choice," the affiliate reported.

The "Choose Life" plates are available in 29 states, according to Choose Life Inc., a nonprofit that helps states that want to sell these specialty plates.